🔢 Math Calculator

📐 How It Works

Calculates the total boundary length of a shape: sum of all sides for polygons, 2πr for circles.

🔢 Worked Examples

• Circle r=7: P ≈ 43.98
• Rectangle 5×8: P = 26
• Equilateral triangle side 6: P = 18
• Square side 4: P = 16

📋 Common Use Cases

• Fencing a yard or field
• Framing a picture or window
• Running track length
• Border material for tiling

💡 Did You Know?

The perimeter of a fractal coastline is theoretically infinite — the shorter your measuring stick, the more detail you capture, and the longer the total. This is the "coastline paradox" described by Benoit Mandelbrot.

⚠️ Common Mistake

Confusing perimeter (boundary length) with area (enclosed space). A 4×4 square has perimeter 16 and area 16 — the same number but different units (m vs m²).